WS-3081 UV/Solar sensor Fix and reset

[ziggy110]

Hello to everyone,
If you are like me then you have probably already tried the reset button many times and put new rechargable batteries in your Thermo Hygro Sensor and gone through the forums trying the different suggestions fowarded by the forum members.

Q. WHY DID MY STATION STOP WORKING?
A. Many reasons probably only the Manufacturer could tell us if we could contact them????

Q. WHY WONT MY SENSOR WORK PROPERLY?
A. Most likely because a proper reset has not been achieved during start up/when you tried to reset it or a low battery. (or you may have a faulty sensor)

Q. WHY DOES THE UV READING FLUCTUATE OR PEAK TO THE MAXIMUM OF 12 WITH LOW SUN?
A. To much light is being received by the sensor (Poorly made)


These Key Points are taken from Set up Guide Page 3 of the weather station manual

*Insert 2xAA 1.5v Alkaline rechargable batteries
*(If no LED light up or is lighted permanently, make sure the battery is inserted the correct way
OR A PROPER RESET IS HAPPENED)

Other points to look at are.....

* The station when you bought it came with 2x 1.2v 2000MAH Alkaline Rechargable Batteries
* The manual tells you to use batteries with a higher voltage than the batteries that were
supplied with the station??
* The sensor runs a 3.0v system
* The Mini Processer crashes causing failure of sensor
* UV/Solar sensor came with a reset button
* No explanation of "OR A PROPER RESET IS HAPPENED"

*********** Now the Easy Fix**************
***See later post for UV Sensor Fix****

* UV Sensor Fix
* Batteries
* Proper reset

You will need

1 x roll Clear sticky tape
1 x Clear cd/dvd Plastic sleeve (its actually foggy to look through,see pics)
2 x AA Duracell 1.2v NiMH 2450MAH Batteries (Note NOT 1.5v)

*UV Sensor fix*
1. Cut a piece 1cm x 3 cm from the clear cd/dvd cover sleeve. (see pic step 1)
2. Check the piece you have cut up against the light it should look foggy. (see step 2)
3. Fold the piece you have cut 2 times, you should have a piece that is big enough to cover the
UV Sensor then wrap a turn of clear sticky tape around the piece to hold it together(see step 3)
4. Remove the plastic outer cover from the UV/Solar sensor.
5. Now tape the piece over the UV sensor of the solar transmitter unit making sure it is stuck
flat over the sensor hole (see step 4).
6. Replace the plastic cover on UV/Solar sensor.

*Batteries*
1. Replace the 2 x 1.2v AA 2000MAH Alkaline batteries supplied with 2 x AA Duracell 1.2v NiMH
2450MAH Batteries.
2. Leave batteries out till you have your sensors all plugged in.

WS-3081 UV Sensor fix easy.JPG

*Proper reset*
1. Plug all the sensors in to their connections.
2. Insert 2 x AA Duracell 1.2v NiMH 2450MAH Batteries into the Thermo Hygro sensor.
3. Press the reset button under the UV/Solar sensor holding for about 10secs.
4. Release the reset button and imediately look at Thermo Hygro sensor and UV/Solar sensors
the red light on BOTH sensors "MUST" light up together. (see pic for reset and red lights)
5. If only one light comes on remove batteries and repeat the process till you get it right.
6. If done right both lights will be on together for a sec or two then the thermo hygro sensor light
will go off first then the UV/Solar sensor about 3 secs later this creates the time between the
two sensors so they do not clash, shortly after they will start the normal cycle sends if
everything is right. (solar sensor flashes twice)
7. Insert the batteries in the base unit(or push the down arrow on the base unit for 4secs) to start
the search for the signal.
8. Check your base to see if you have all readings this may take a minute or two.
9. If all is going well you should see all sensor readings and the UV readout should be close to the
Official readings for your area.

WS-3081 Reset light.jpg

The light has been reduced but not stopped to the UV sensor preventing the processer overloading and trying to recover from the constant changes and High peeking on overcast days
which was most likely adding to the crashes of our sensors.
I was unable to get a reset using 1.5v AA Alkaline rechargable batteries so I used 1.2v 2450MAH NiMH batteries which looks like have helped with the extra power drains the processer has at times.
My station has not missed a beat since doing this fix and I have very reasonable readings from my UV Sensor in comparison to the Official Weather UV readings for my area. Summertime will give me the readings I need to see if it is a winner or I need another layer of plastic over the UV sensor or try a different material. Only time will tell.......

Hope this helps others as it has worked good for me!

Peter.

[AllyCat]

Hi Peter,

Thanks for that information and welcome to the forum. It's a pity the photos are rather large (I don't know many people who run 4000 x 3000 pixel monitors).

Just a few comments, perhaps more relevant to those of us in the UK than Australia.

Rather than "normal" NiMH AA cells, I recommend the "Hybrid" type which are often a similar price and nominally have a slightly lower capacity (usually 2100 mAh) but much lower self-discharge which may better help to get over a UK winter. Sold under various trade names with features such as "Pre-Charged" or "Low leakage", etc..

Two 1.2 volt cells might not give sufficient wireless range in some applications (and the "Low TX" icon being ON permanently may annoy some people) in which case the solution is to use a pair of Lithium NON-rechargeable AA cells which are expensive but should run for many years (unless the Pod has the "excessive power consumption" fault, another of the well-known issues with the 3080/1).

In the UK most models are the 3080 with a Radio Controlled Clock which makes the power-up/reset sequence even more complex, because the first thing that the external "Transmitter" module attempts to do is to receive the RCC data for several minutes.

Cheers, Alan.

PS: Rechargeable Alkaline cells are normally 1.5 volts, if they measure as low as 1.2 volts they're useless and are NOT likely to recharge again satisfactorily. But don't pay a high price for replacement RAs which are fundamentally very similar to normal "non-rechargeable" Alkalines.

[ziggy110]

Gday Alan,

WOW that picture was rather large I have edited a smaller version this time

Thanks for your comments in regards to the batteries. I guess this will differ for everyone depending on whats available to them in their part of the world.
My experience with the 1.2v batteries so far have been ok as I replaced the original Batteries (1.2v)because the Low TX light was on and was unable to get a proper reset with 1.5v batteries, however with the AA Duracell 1.2v NiMH 2450MAH replacement batteries the Low TX light went off after a good couple of hours of sun over 2 days and has not come on since then,but this could well change with less hours of good sunlight.
The Low TX light going out at least proves the little solar panel is working.

I will play around with the battery side of things a bit more I guess when these fail.

Regards
Peter.

[AllyCat]

Hi Peter,

Were there any markings on the original cells (manufacturer, voltage, mAhrs, technology)? FO "normally" supply 1.5volt, 2,000mAh, Rechargeable Alkaline cells, but maybe a retailer supplied/substituted something different. Rechargeable Alkalines are cheap for the manufacturer to obtain, but difficult/expensive to buy elsewhere and their performance is so poor that NiMH are a better substitute.

Were your supplied batteries actually 1.2 volts when received (i.e. Low TX icon on) or did it take a few weeks/months? There seem to be three possibilities:

1. The supplied cells were already (partly) discharged and/or are rubbish (quite a high probablilty). A 2,000mAhr battery should run the transmitter for at least a year even without solar assistance.
2. NiMH cells (excluding Hybrids) are normally supplied (nearly) discharged and the winter sunshine was insufficient to charge them.
3. The FO Solar Pod was draining excessive current from the battery (my experience).

Measurements on my Pod showed that it has a voltage regulator at about 3.0 volts (1.5 volts per cell) but the (first, faulty) Pod drained about 300uA continuously and killed the batteries in about 3 months. The drain by a second, replacement, Pod is negligible.

3.0 volts is a little low to charge Rechargeable Alkalines (if they get significantly below that voltage they fail to charge successfully) but slightly high for NiMH or NiCd cells. Some people may be paranoid about overcharging cells (Lithiums do need more care), but IMHO the amount of energy from that small PV cell is perfectly "safe".

My belief is that the batteries in your Pod will work fine for the summer (subject to any other possible issues) but you might experience low voltage again next winter (if it suffers from fault 3. above). If you have a "1 year warranty" situation, it might be worth trying to measure the (dark) drain from the battery. I've described my method previously on the forum, but I can outline (or find) it again if you wish.

Cheers, Alan.

[ziggy110]

Hi Alan

The supplied cells with my unit were 1.2volt, 2,000mAh, Rechargeable Alkaline with a plain yellow wrapper that showed the low TX light after just 2 days probably because of the pod drain or shipped flat. I will spend some time reading your previous notes in the other forum regarding the batteries. Sounds like some interesting reading ahead

*UV Sensor Fix*

********************UPDATE TO UV SENSOR FIX**************************
******See later post for UV Sensor Fix*******



I have included a picture of the UV readings I had prior to my UV fix and after adding the fix.
Also have added the official UV readings and plotted them along with my new readings in the bottom of the pic. As you can see after midday when the sky cleared the uv readings were close enough for a cheap weather station and an easy fix! Its a pitty these things were not made right in the first place

Cheers
Peter

Uv Project.jpg

[ntinos]

Two 1.2 volt cells might not give sufficient wireless range in some applications (and the "Low TX" icon being ON permanently may annoy some people) in which case the solution is to use a pair of Lithium NON-rechargeable AA cells which are expensive but should run for many years (unless the Pod has the "excessive power consumption" fault, another of the well-known issues with the 3080/1).

Ηi Allan
My opinion is not good idea to use someone Lithium ,or alcaline NON-rechargeable AA cells,because the solar charger it make damage to lithium - simple alcaline battery.

Friendly

[AllyCat]

Hi,

The unit which I tested actually regulated the voltage from the PV cell to approximately 3.0 volts, so there is little risk of "overcharging" non-Rechargeable Lithium or Alkaline cells. The way I "discovered" this regulation was when I found that my Solar Pod was NOT feeding any "charging" current into a pair of new Alkaline cells.

The "safest" solution might be to disconnect the PV cell (when using non-rechargeable batteries), but the chemistry of non-rechargeable Alkalines is almost identical to that of the so-called "Rechargeable Alkaline" type (and a pair of Primary Lithiums should maintain their voltage above 3.0 for many years in this application).

Cheers, Alan.

[ntinos]

The "safest" solution might be to disconnect the PV cell (when using non-rechargeable batteries)

Cheers, Alan.

Hi Allan
I Agree ,or we can put a diode e.g 1N4001 anastroph polarity to positive cable,for cut the voltage from solar panel.

I like this station,with little mod at UV sensor,and a fan aspirated radiation shield for out thermo/hygro sensor for correct measurements is a good and cheap total,i do not know if it is creditable without problems.I mean electronic problems

[ArjanH]

Hi

After 2 months of working perfectly my Light/UV module started freezing up a few weeks ago. I guess it has something to do with the fact that when I installed it it was the middle of winter and therefor relatively low light intensity.

Instead of using the cd cover I used some squares cut out of a plastic milk bottle. I am currently using 4 layers and it appears to be doing the trick although it is hard to tell if it has permanently fixed the problem. It has made no difference to the UV ratings which very quickly jump to the maximum 12 (for instance it is now 8:15 AM and already we are at 7) but at least it doesn't immediately lock up anymore like it has for the last few weeks.

The reason I am posting this is the batteries. I have done a fair bit of reading on 1.5 Volt chargeables and it appears they are probably a bit of a myth. There are no known "reputable" manufacturers of 1.5 volt rechargeable AA batteries that I can find in any case. I considered using a single 3.7 Volt LIFE AA but think that this will probably be too much for the circuit so have opted for the good quality energizer AA 1.2 volt NIMH's. We'll see how long they last.

I am just wondering if ziggy110 can give us an update on how he/she is going.

Cheers

Arjan

[AllyCat]

Hi Arjan,

A slightly old thread, so I can add some additional information. Several people have reported that it is a high level at the Lux sensor (the white dome) which is responsible for the lockups. However, it is the UV sensor (the tiny chip to the lower left of the sloping PV panel) which over-reads badly. But personally, I have abandoned any attempts to obtain "useful" measurements and have located my solar pod in a "shady" location to avoid direct solar heating of the temperature sensor. Also, I believe that the UV sensor measures UVA/B rather than the "correct" predominantly UVC wavelengths.

Certainly (IMHO) rechargeable alkaline cells are a "poor" rechargeable technology, but Nickel-Zinc cells are available in AA geometry. They deliver a nominal 1.6 volts and are often rated in "Watt-Hours" (to make the numbers look better) but the samples I measured were only around 50% - 67% of their "rated" capacity. However I didn't really have a suitable charger for this rather unusual technology.

Normal Lithium Polymer cells deliver a nominal 3.7 volts, but are typically charged up to 4.2 volts which is probably too much for the FO transmitter. However, a single Lithium Iron Phosphate (LiFePO4) cell seems to be an excellent replacement for rechargeable alkalines (with a short-circuit "placeholder" cell in the second bay). The "freshly charged" voltage can be around 3.7 volts, but that's no worse than a pair of non-rechargeable lithium AAs which many people use.

Unfortunately these "unusual" technologies can be hard to obtain, generally only from China/HK (which is perhaps less inconvenient for Australasia than UK), but LiFePO4s sometimes can be found described as a "replacement for solar garden lights", often as the "14500" (dimensional) cell type rather than the equivalent AA.

So to summarise, if the FO transmitter works well from a pair of NiMH cells (preferably the "hybrid" low-leakage type, at least for higher latitudes) and a "Low Battery" icon is not an issue, then use those. Otherwise try to obtain a single LiFePO4 + a placheolder (dummy) cell, but it may be necessary to bypass the voltage regulator in the FO pod which seems to be set too low even for the intended rechargeable alkalines (a LiFePO4 does not need a regulator with the power available from the tiny PV panel).

Cheers, Alan.

[ziggy110]

Hello Arjan & Alan

Good to see you have tried different things for your UV Sensor. This is what I can tell you from my experience so far with the WS-3081.
Since my original post I tried many things to get the weather station to work reliably. It now runs well enough to be very usable
I have made a Solar Fan Aspirated Radiation Shield for better temperature readings and moved the rain gauge of the mast (to stop the wind registering as rain)

Weather station.jpg

Weather station 2.jpg

Batteries Update
I have found with using 1.5v batteries I was getting an erratic reading with my Temperature & Humidity readings. Each reading would go up and down the Humidity would fluctuate by 1 and the temperature was around 1.2 degrees this would make my history graph readings look more like the teeth on a cutting saw lol. As I stated on my previous post I now "only use 1.2v batteries" with excellent results! Now my History graph looks as it should.

UV Sensor Update
After trying many different items I came across this (pics attached) I now use a piece cut from a cheap pair of plastic (Red/Blue) 3D glasses I had previously bought of eBay for about 2 dollars. The Red lense made very little difference to the readings (still high) But the Blue Lense gave me very good results. This has now been working and not had any problems since not long after my original post with the sensor. (Got through an Australian summer)

IMG_20130912_125756.jpg

IMG_20130912_125448.jpg

The ONLY PROBLEM I have had since is on the odd occasion the BASE UNIT has needed to be reset (stopped talking to my Pc??) No worries with the Sensors.

Hope this helps & makes sense

Peter

[Korban_Dallas]

Hi folks
i have read with interest the fixes for the solar sensor and have tried all of them with unfortunately with little success
It still kept going off line
And never one to give up i came up with my own fix that may or may not help but it certainly has worked for me

From what I understand reading the above posts is that the U/V processor gets overloaded

The sensor location on the device means it sits in a 1mm recess molded into the housing
This allows Light/UV to fall on the sensor from a very wide arc

So what I have done is taken the plastic top of a pen



Cut about 5mm of of the end




And then glued that small piece round the sensor like a cowl and reassembled
Sorry
i don't have a picture of that
And it's now been running all day with no problems when it usually only lasted an hour
It's been hot here today, lots of bright sunny weather and big patches of overcast passing by and
The device hasn`t faltered once the readings seem a bit flighty but will need to check that

Something to try at least

[Korban_Dallas]

Hi folks

Just a quick update

The sensor has now been up about 24 hours and seems solid as a rock now U/v readings seem consistent with met office figures
Light level (Lux) seems to be consistent with outdoor conditions IE as the light level drops so does the reading and vice verse
As for its light level accuracy I have no idea how to test that

But it hasn`t locked up or gone off line since the fix I applied

i surmise that narrowing the view field of the sensor and restricting its detection area to a vertical input (like a telescope) fixes the problem

[AllyCat]

Hi,

As for its light level accuracy I have no idea how to test that

That's not too difficult if you're (very) patient. Wait for a day with "clear skies" and compare the "Solar Radiation" curve with the "Max Solar Rad" in Cumulus' "Select a Graph". Here's an example from my 3080, now that I've mounted the "Solar Pod" at the top of the mast with the wind sensors.

GoodSolarLux.png

Note that if there are any "white" clouds in the sky, then obviously the light level often will be lower, but it also can be higher than the theoretical maximum. The "kink" at ~200 W/m2 is puzzling and repeatable; I haven't yet resolved if it's an artefact in the Pod or some external effect. But I suspect that the "diffuser" (white dome) is not actually doing a very good job, because the curve matches the Cumulus graph which strictly applies to a "flat plate" collector, not to diffused light (Lux).


My 3080 has only ever suffered two "lockups" (going "off line" and requiring a reset to the Pod ) in as many years, so I don't have much "evidence" concerning the issue. On both occasions it was at high light levels near mid-summer, but after the first lockup I added a piece of PVC tape over the UV sensor and it now never reads more than "4". So the second lockup suggests that the UV is not the only cause. Maybe a very high Lux value can also cause a "numerical overflow", perhaps the battery voltage gets too high, or the Pod just gets too hot, or maybe it's an "unfortunate" combination of several different factors?

Cheers, Alan.

[Korban_Dallas]

Hi AllyCat

Thanks for that
Very, very patient
I live in Scotland a day with "clear skies" can be a very rare thing indeed